I don't think you have to buy a whole new EHA, just buy the o-rings and replace those. I'm not sure, but I think some fine-tuning on the fuel injection is necessary after removing and replacing the EHA. Not 100% on this, just basing it on posts I've read here. Cheers!

__________________
Streetside: 1987 Mercedes 300E Petrol Blue/Green
2014 Ford Mustang Grabber Blue
1999 Ford Ranger Green

Dockside: 1968 Eltro 17
1985 Silverton 34C